Extendable rod antenna and helical antenna with frequency adjusting conductor
US5859617A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 7, 1997 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Feb 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q11/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The invention is directed to an antenna assembly which, when a rod antenna unit is retracted in the radio housing, permits transmission and reception with no influence thereon by the retracted rod antenna unit and which resonates with two frequencies when the rod antenna unit is in its extended position. Feeding metal pipe (9) connected to a secondary antenna (14) formed by a helical antenna element has contact springs (18) for elastic contact with a rod antenna unit (2). When the rod antenna unit (2) is retracted position, the contact springs (18) contact an insulating cover (11) wrapped around the rod antenna unit (2), electrically disconnecting a primary antenna (20) from the feeding metal pipe (9). Hence, only the secondary antenna (14) serves as an antenna without being affected by the primary antenna (20). When the rod antenna unit (2) is in its extended position, the contact springs (18) make electrical contact with a connector terminal (22) electrically connected to the primary antenna (20), thus connecting the primary antenna (20) and the secondary antenna (14) to the feeding hardware (9).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.